#include<bits/stdc++.h>
using namespace std;
int n,r[100005],ans;
bool vis[100005],o[100005];
int main()
{
    freopen("duel.in","r",stdin);
    freopen("duel.out","w",stdout);
    cin>>n;
    for(int i=1;i<=n;i++)
    {
        cin>>r[i];
    }
    sort(r+1,r+n+1);
    for(int i=1;i<=n;i++)
    {
        if(r[i]<r[i+1]&&vis[i+1]==false&&o[i]==false)
        {
            ans++;
            o[i]=true;
            vis[i+1]=false;
        }
    }
    cout<<ans<<endl;
    return 0;
}
